Guest: Hélène-Chartier, C40 Cities, France

Key Takeaways

• Healthy Cities are built neighborhood by neighborhood. Urban planning needs to be strategic for housing, infrastructure, and risk management; however, that approach is incomplete without bottom-up neighborhood planning shaped by residents’ needs. The neighborhood revolution sits at the intersection of climate action, public health, and social inclusion.
• Daily exposures to heat, pollution, walking conditions, food access, and social contact are experienced more frequently at the local level than at the citywide scale.
• Neighborhood transformation can deepen inequality if benefits are concentrated in already advantaged areas or if upgrading leads to displacement.

Summary

1. Neighborhood improvements are more than just beautification processes:
   • • They should improve health, mobility, the local economy, and social inclusion at the same time.
     • Tactical urbanism should be used as a method, not an endpoint. Temporary interventions are useful because they allow cities and communities to test ideas cheaply, reveal hidden problems, and build evidence for more permanent investment.
     • Community participation should not be treated as consultation after the fact. Communities should be involved in diagnosis, co-design, implementation, and sometimes even maintenance.
2. Built form is directly linked to public health. More walking, better access to green space, reduced traffic danger, more shade, lower heat exposure, and better access to food and basic services can all improve health.
3. Neighborhood interventions are strongest when they combine physical design, social participation, and institutional continuity. A few examples include:
   • • Rio de Janeiro
       • The Oswaldo Cruz Urban Lab worked through a participatory process with schools, residents, neighborhood associations, quilombo communities, municipal actors, and university partners. 
       • The project moved through co-creation, design validation, implementation, evaluation, and activation. 
       • Its outputs were small-scale but multi-layered. Widened sidewalks, crosswalks, murals, community gardens, planting beds, new seating, and local fabrication of urban furniture were built through repeated community involvement and a strong link between municipal action and neighborhood knowledge.
     • Nairobi
       • The Dunga Road Renewal Project approached the street as a lived social space, not just a traffic corridor. 
       • The process began with women and girls assessing access, safety, comfort, and environmental conditions, which is important because their day-to-day experience of the street revealed issues that a purely technical traffic survey might miss. 
       • Young artists then translated those observations into temporary interventions like murals, seating around a tree, protections for exposed roots, and a bench integrated with the boda-boda environment. 
       • The project found that people were already creating informal pedestrian crossings because the formal street design did not serve them. That observation led to the creation of a formal crosswalk and related public realm improvements.
     • Buenos Aires
       • In Vicente López, the healthy food project used neighborhood scale to address access to nutritious food. 
       • The intervention was built around creating a network of local producers and healthy shops; generating demand through workshops in schools, kindergartens, and community centers; and activating the neighborhood through events that made the new supply visible and socially desirable.
       • The most important outcome was the durable commercial relationships that led to shops permanently carrying products from local producers.
       • The project shows how a health-oriented project can also rewire local supply chains.

How can Cities apply these learnings?

1. Run co-creation processes with residents, schools, local businesses, women, youth, and community organizations.
2. Pair design pilots with monitoring so cities can learn what changed in use, safety, comfort, and local commerce.
3. Involve multiple departments from the start: planning, mobility, public works, environment, health, education, and culture.
4. Use local procurement and local labor where possible, so neighborhood upgrades also support local economic activity.
5. Build scaling logic into the pilot. The goal should not be to produce one attractive site; it should be to create a repeatable method.

Ideas for future research

1. Study what makes pilots scale and measure how informal or unplanned behavior can change formal design.
2. Investigate the displacement risk of neighborhood upgrading, especially when successful interventions increase desirability in already pressured housing markets.